Blank feeders

ABSTRACT

The invention provides a feeder for thin card or like blanks having a table over which the blanks travel and with air jets for preventing the blank moving one way and also suction means for preventing the blank moving the other way, the two combining to hold the blanks in the desired plane.

United States Patent Thomas Desmond Bishop Solihull, England [21] Appl.No. 799,683

[22] Filed Feb.l7, 1969 [45] Patented Mar. 30, 1971 73] Assignee The Deritend Engineering Company Limited Birmingham, England [72] Inventor [54] BLANK FEEDERS 2 Claims, 4 Drawing Figs. [52] U.S. Cl 271/26 [51] Int. Cl B65h 3/08 [50] Field ofSearch 271/26, 76, 69

[56] References Cited UNITED STATES PATENTS 1,460,314 6/1923 Deck 198/26 1,575,892 3/1926 Ashby 271/26 2,261,971 11/1941 Matthews 271/76 3,380,7 4 4/1968 Laumer 271/76 Primary Examiner-Richard E. Aegerter Attarney-Marshall and Yeasting ABSTRACT: The invention provides a feeder for thin card or like blanks having a table over which the blanks travel and with air jets for preventing the blank moving one way and also suction means for preventing the blank moving the other way, the two combining to hold the blanks in the desired plane.

Patented March 30, 1971 2 Sheets-Sheet 1 Patented March 30, 1971 2 Sheets-Sheet I This invention relates to blank feeders, that is, apparatus for feeding blanks of sheet, card, board or other material for or after treatment by printing, die-cutting or analogous rotary means. With relatively thick board, single feed rolls may serve to maintain blanks in a desired plane, but thin stock is more difficult as it tends to curl or flap if not supported. This problem is acute in the case of strippers and die cutters.

The objects of the invention are to provide improved means for maintaining blanks in a desired plane during feeding.

In accordance with the invention, apparatus for treating blanks comprises at least one roll pair and means for feeding the blanks in a desired plane relative to the roll nip, said means comprising a guide member extending towards the nip, means for blowing air through or about said member, and means for creating suction to draw a blank towards said member.

Where the invention is associated with a-roll pair on the outgoing side of the nip, there is or may be a tendency for the blanktofollow one of the rolls and depart from the desired feed path. The said member may be wedge-shaped to extend in towards the nip but it must be located with a clearance between it and the rolls, and the blank may travel through the clearance: preferably therefore, air is discharged under pressure to flow through this clearance towards the nip from spaced nozzle bores, and this may cause the blank, at its leading ,edge, to move in the opposite direction away from the desired feed path. The suction means restrain this movement and cause the blank to slide on said member.

Suction may be provided at desired points by using bores which communicate between the pressure passages (i.e. the clearance or passages actually connected to the air pressure source) and the surface, and the bores may intersect the passages at acute angles so that air in the bores is entrained, and venturis may be provided to assist in this. Alternatively a suction fan may be provided or the fan which provides the pressure may also provide the negative pressure or suction.

Whilst pressure and suction are only necessary when the leading edge of the blank approaches the surface, it may be more convenient to provide continuous pressure and suction whilst the treatment apparatus is running.

One embodiment of the invention is now more particularly described with reference to the accompanying drawings wherein:

FIG. 1 is a fragmentary view, in elevation, showing part of a treatment roll nip, the feeder mechanism, and a pinch roll pair;

FIG. 2 is a fragmentary plan view of the mechanism, with parts broken away for clarity;

FIG. 3 is an enlarged sectional view on the line 3-3 of FIG. 2; and

FIG. 4 is an enlarged sectional view on the line 4-4 of FIG. 2.

Referring now to the drawings, the treatment roll pair comprises rolls 10, 11, which may be printing rolls, die-cutting rolls, or other treatment rolls. The material being treated is in sheet form and is intended to travel in the direction of line A-B, FIG. 1, and in the direction of arrow C, from the roll pair to and through feed roll pair 13, 14. As a result of gravity, sticking or other forces, there is sometimes a tendency for the sheet to droop, particularly at the leading edge as it emerges from the nip of rolls l0, 11. As soon as the edge is between the nip of the feed rolls l3, 14 the difficulty is substantially over. Usually the feed rolls are located as close as possible to the treatment rolls to minimize the problem but it cannot be wholly overcome by this.

In accordance with the invention mechanism is provided between the two sets of rolls to overcome the difficulty.

The mechanism comprises a guide plate 20 to which is secured a downwardly inclined nose strip 22 by screws 24, and the plate is bolted to a vortex plate 26 and to an air channel 28 and the plate 26 and channel 28 are also secured together.

The air channel 28 is fed from one or both ends by pipes 32 supplying air under pressure from a blower (not shown). The channel is bridged by supporting struts 34 and is slotted, at intervals along its length, immediately below the guide plate, as indicated by references 36. The vortex plate has a series of spaced chambers 40 opening to the slots 36 laterally and at the opposite edge a series of parallel bores 42 open below the guide plate. Hence air is fed under pressure to emerge in a series of jets and flow below the guideplate and its nose strip and into the roll nip. The nose strip has a castellated edge and some air flows through the castellations. Hence, if the leading edge of the blank being fed droops, it tends to be blown upwardly so as to clear the nose strip, but only the zone of blank between the nip and strip is subjected to substantial force from this source.

Because of boundary layer effects due to the speed of the moving blank, air tends to travel with the blank and between it and the upper surface of the guide plate and maintains the blank above the guide plate.

The chambers 40 are separated by bosses 50 which are blind bored normally of the guide plate to form vortex chambers 52 and the guide plate has like aligned bores 54. Parallel to bores 52, 54 are aligned bores housing valve plugs 56. Plugs 56 have enlarged heads provided with diametric slots 58, and are transversely bored at 60, the bores lying in the same planes as the slots. The plugs carry O-rings 61 and are held in place by cotters 62. Passages 64 open tangentially of the vortex chambers at their base and intersect the axes of the plug bores, extending therebeyond to a channel lying between the vortex plate 26 and the air channel 28 and the channel 70 is connected at its ends as best seen in FIG. 2, to pipes 72 connected to suction means (not shown).

Suction created in the channel is communicated to each vortex chamber to an extent dependent upon the angular setting of the valve plugs, and the alignment of the slot and bore in each plug facilitates valve setting. Hence air is drawn into each vortex chamber and due to the tangential disposition of the passages 64 this tends to be in a spiral flow downwardly about the chamber periphery, and hence creates suction areas in the vortices produced. Hence the blank tends to be drawn downwardly towards the guide plate.

It will be appreciated that as well as adjusting the valve plugs, the suction and blower means may be controlled, and effects can be finely balanced so that the sheet is fed in a plane parallel to the guide plate surface and held in that plane by the balanced forces without deviating therefrom.

Further, although the invention is described in relation to the outgoing side of the treatment nip, it'can equally well be used on the ingoing side of the nip.

The foregoing description is based on the use of a suction fan applied via pipe 72. However, it is equally feasible, and may be preferred, to connect pipe 72 to the main fan or a further fan and blow, that is apply positive pressure through the pipe. In this event, the air emerges as jets through the tangential bores to the vortex chambers, and results in spiral upwards flow of air therein. The vortex thus created results in suction at the central areas of the vortices, to the same effect.

Iclaim:

1. Apparatus for feeding blanks in a desired plane, comprising at least one roll pair, a guide member which has a substantially flat upper surface and which extends toward the nip of a roll pair, means for blowing air beneath the guide member toward the nip of the roll pair, a plurality of vortex chambers formed as depressions in such upper surface, and a passage connected tangentially to each vortex chamber for conducting a flow of air to produce a vortex, creating suction at the center of the vortex to hold a moving blank in a plane parallel to such upper surface.

2. Apparatus according to claim 1 wherein each tangentially connected passage is provided with a valve for controlling the flow of air therethrough. 

1. Apparatus for feeding blanks in a desired plane, comprising at least one roll pair, a guide member which has a substantially flat upper surface and which extends toward the nip of a roll pair, means for blowing air beneath the guide member toward the nip of the roll pair, a plurality of vortex chambers formed as depressions in such upper surface, and a passage connected tangentially to each vortex chamber for conducting a flow of air to produce a vortex, creating suction at the center of the vortex to hold a moving blank in a plane parallel to such upper surface.
 2. Apparatus according to claim 1 wherein each tangentially connected passage is provided with a valve for controlling the flow of air therethrough. 